The invention relates to an apparatus for producing parallel-walled grooves in green areas and lawns.
An apparatus of this kind is described in German patent document DE-AS No. 12 72 612. In this arrangement grooves which cross one another at spacings of approximately 15 to 60 cm are milled into the surface of the lawn by a rapidly rotating milling disc, which is of star-like construction and carries cutting tools at the outer ends of the arms of the star. These milling tools lift out the earth over the entire width of the groove and this is intended to result in a parallel-flanked cut. In practice however, parallel-flanked grooves are not formed when using a milling disc of this kind. Instead, grooves with broken-out walls are formed, and earth from the walls can refill partially the grooves.
In contrast, the invention is based on the object of providing grooves of a predetermined and changing depth relative to the ground. With the invention the walls of the grooves generated are uncompressed and cut out smoothly, so that adaptation to the various types of ground, different moisture conditions, changing scar densities and other factors is ensured.
With this apparatus it is possible to sow the seed so that ideal growth conditions are obtained. Accordingly the seed is deposited at predetermined periodically changing depths in the grooves in order to free the seed from pernicious effects of old grass or vegetation.
Furthermore, there is the decisive advantage of being able to automatically deposit the seed at various depths which reduces the sowing risks to a quite considerable degree when unfavorable weather conditions prevail. This is so because the seed grains which lie flat start to grow relatively quickly, whereas the seed kernels which lie at greater depths germinate in a stepped time sequence, with the grains at the troughs of the grooves starting to grow last. Moreover, the largest moisture reserves are present in the deep layers and this is also helpful in controlling sowing plans.
One embodiment in which runners are mounted between cutting knives resultss in a resilient sliding support between the knives which cut the slits on the ground to improve the slit formation.
These runners are preferably constructed as carriers for capping shares, which follow the knife blade pairs and cut free the groove which is created, prior to planting the seed automatically behind the capping or clearance shares.
The design according to the present invention meets all the requirements which arise in practice and which can be adapted by simple reversal or replacement of tools to meet the most diverse requirements for ideal seeding, without ignoring important considerations such as the working width, the quantity of seed and the seed spacing.